New Zealand First is refusing to take part in the Government's constitutional review.
The review is looking into matters such as the size of Parliament, Maori representation, the role of the Treaty of Waitangi and whether New Zealand needs a written constitution.
But New Zealand First leader Winston Peters says it is sham designed to sneak the principles of the Treaty of Waitangi into all laws.
He says the constitutional review is a political stunt from the National and Maori parties, and is not designed to give people more say in the country's democracy.
Mr Peters says New Zealand First has declined an invitation to nominate a party member to take part in the review, which is due to report back to the Government by the end of 2013.